1. Field of the Invention
The present invention relates to a timepiece having a mainspring winding state display apparatus having a function of displaying a state of winding a mainspring constituting a power source of a mechanical time piece. Particularly, the invention relates to a timepiece having a mainspring winding state display apparatus constituted to be able to arrange a mainspring winding state display member (power reserve indicator) at an arbitrary pertinent position in a movement of the time piece.
2. Description of the Prior Art
(1) A Time Piece Having a Mainspring Winding State Display Apparatus of a First Type of a Background Art.
A time piece having a mainspring winding state display apparatus of a first type of a background art includes a mechanism (power reserve mechanism) for displaying a remaining time period in which a mainspring can operate, that is, a duration of the timepiece. Such a power reserve mechanism uses a planetary gear mechanism for reciprocating a hand for displaying the duration of the timepiece in a fan-like shape. The timepiece having the mainspring winding state display apparatus of the first type of the background art is constituted by a ratchet wheel, a planetary gear mechanism constituted by a planetary intermediate gear brought in mesh with a barrel complete, a planetary wheel rotatably attached to an eccentric portion of the planetary intermediate gear, a sun gear brought in mesh with a planetary pinion, and a second sun wheel brought in mesh with a planetary gear, a display transmission wheel brought in mesh with a sun pinion, a display wheel brought in mesh with a display transmission pinion, a display degree determining pin, and a planetary transmission wheel brought in mesh with the ratchet wheel and a second sun gear (refer to, for example, JP-A-9-21886).
(2) A Timepiece Having a Mainspring Winding State Display Apparatus of a Second Type of a Background Art.
A timepiece having a mainspring winding state display apparatus of a second type of a background art is provided with a planetary intermediate gear provided to be able to rotate by rotation of a barrel complete gear, a planetary wheel rotatably provided to the planetary intermediate gear by constituting a rotational center at a portion different from a rotational center of the planetary intermediate gear and having a first planetary wheel and a second planetary wheel rotatable integrally, a first sun wheel rotatably provided by constituting a rotational center by the rotational center of the planetary intermediate gear and having a first sun gear brought in mesh with a second planetary wheel, a second sun wheel provided rotatably by constituting a rotational center by the rotational center of the first sun wheel and having a second sun gear brought in mesh with a ratchet transmission wheel and a second sun pinion brought in mesh with the first planetary wheel, a claw wheel attached to the first sun wheel and having one or more feed claws, a winding mark intermediate wheel provided rotatably intermittently by the feed claw, a winding mark jumper for rectifying a position in a rotational direction of the winding mark intermediate wheel, and a mainspring winding state display member (power reserve indicator) for displaying a mainspring winding state based on rotation of the winding mark intermediate wheel (refer to, for example, JP-A-11-183642).
According to the timepiece having the mainspring winding state display apparatus of the background art, a rotational center of the mainspring winding state display member (that is, winding mark hand: power reserve indicator) is arranged at a vicinity of a rotational center of the barrel complete gear. Therefore, in the timepiece having the mainspring winding state display apparatus, with regard to arrangement of a plurality of indicators (hour hand, minute hand, second hand, winding mark hand or the like), there is a restriction in view of design. Further, in the timepiece having the mainspring winding state display apparatus of the background art, when the rotational center of the mainspring winding state display member is arranged at a position remote from the rotational center of the barrel complete gear, rotation needs to transmit from the barrel complete gear to the mainspring winding state display member via a wheel train. According to such a structure, backlashes of mesh are present among the plurality of gears, and there poses a problem that operation of the winding mark hand (power reserve indicator) is retarded.
It is an object of the invention to provide a timepiece having a mainspring winding state display apparatus such that a rotational center of a winding mark hand (power reserve indicator) can be arranged at an arbitrary pertinent position in a movement of the timepiece regardless of a position of a rotational center of a barrel complete gear.
It is another object of the invention to prevent the operation of a winding mark hand (power reserve indicator) from being retarded by reducing influence of backlashes of mesh among gears for transmitting rotation to the winding mark hand (power reserve indicator) in a timepiece having a mainspring winding state display apparatus.
It is still another object of the invention to provide a small and thin timepiece having a mainspring winding state display apparatus in which a restriction in view of design is very inconsiderable.